This invention relates to a device for sensing the amount of alternating current flowing through a conductor or set of conductors to an electrical load and to a related monitor for turning on a warning, indicating, control or some other device if the current level exceeds or drops below a preset value for longer than a specified period of time.
The sensing device and monitor of this invention can have numerous applications, one of which is to sense the amount of current consumed by an electrical utility customer, particularly a customer who is charged by the utility in accordance with the peak power consumption experienced by the consumer during a given billing period. The device of the invention can be used by such a customer to warn him if the current level of the electrical power supplied to his house or other building has exceeded a certain peak demand level thereby allowing him to shut off certain appliances or other power consuming devices to bring the current level below the peak demand level before the peak demand level is exceeded for a sufficient period of time as to incur a higher billing charge. Of course, the invention can be used in any other application wherein it is desirable to provide a warning or indication when the current flowing through an electrical conductor or set of conductors exceeds or drops below a preset value for a preset amount of time.
An object of the invention is to provide a current sensing device and monitor which is relatively simple and of low cost construction so as to be easily affordable to general utility customers as well as to other users.
Another object of the invention is to provide a current sensing device which is of simple low-cost construction and which may be used in conjunction with a current carrying conductor or conductors without the need for disconnecting the conductor or conductors, thereby allowing the sensor to be operatively associated with the conductor or conductors with great ease.
Furthermore, an object is to provide such a current sensor which does not surround the conductor or conductors and which avoids the hazards of common current transformers.
Another object of the invention is to provide a current sensing device and monitor which may be packaged as a small unit readily capable of being housed in or near the electrical circuit breaker or fuse box of the usual home, and which monitor may include provision for a remote alarm whereby the alarm may consist of an electrically operated visual, audible or control device plugged into any selected branch circuit of the home.
Other objects and advantages of the invention will be apparent from the following description and from the appended drawings forming a part hereof.